Roller mill

Abstract

Described is a roller mill ( 1 ) for grinding particulate material, such as cement raw materials, cement clinker and similar materials, said roller mill comprising a substantially horizontal grinding table ( 3 ), at least one therewith interactively operating roller ( 4 ) which is configured for rotation about a roller shaft ( 6 ) through the use of a bearing ( 7 ) for the roller, and a closed circulation system for lubricant for lubricating the bearing ( 7 ) for the roller, said circulation system comprising a reservoir ( 9 ), ducts ( 10 ) for feeding of lubricant to the bearing ( 7 ) for the roller and ducts ( 11 ) for recirculating the lubricant from the bearing ( 7 ) for the roller. The roller mill further comprises an autogenously regulated pressure pump means ( 20 ) which is driven by the rotation of the roller ( 4 ), and has a first part ( 21 ) which is mounted on the roller shaft ( 6 ) and a second part ( 22 ) which is mounted on the roller ( 4 ) and rotates therewith. During the operation of the mill the pump means delivers a significant pressure contribution for recirculating the lubricant to the reservoir, and has a capacity which is proportional to the rotational speed of the roller and hence the lubricant requirement.

1. A roller mill for grinding particulate material, comprising cement raw materials and cement clinker, said roller mill comprising:
 a substantially horizontal grinding table, 
 at least one roller that operates interactively with said table, said at least one roller configured for rotation about a roller shaft through the use of a bearing for the roller, said bearing having an outer end, and 
 a closed circulation system for lubricant for lubricating the bearing, said circulation system comprising a reservoir, ducts for feeding of lubricant to the bearing, a duct for recirculating the lubricant from the bearing, a pump means which is driven by the rotation of the roller, said pump means comprising a first part which is mounted on the roller shaft and a second part which is mounted on the roller and rotates therewith. 
 
     
     
       2. The roller mill of  claim 1 , wherein the pump means is fitted in exact axial position relative to the outer end of the bearing. 
     
     
       3. The roller mill of  claim 1 , wherein the pump means comprises a first part that is mounted on the roller shaft, a second part mounted on the roller, a gear wheel pump fitted on the first part, and a gear rim fixed to the second part, said gear rim serving to drive the pump means. 
     
     
       4. The roller mill of  claim 3 , wherein the first part comprises a plurality of ducts for feeding lubricant from the bearing to the gear wheel pump and at least one duct for feeding lubricant from the gear wheel pump to the ducts for recirculating the lubricant to a reservoir for the lubricant. 
     
     
       5. The roller mill of  claim 1 , wherein the pump means is a centrifugal pump in which the second part is provided with force-transmitting means to transmit a force to the lubricant so that it is thrust in the direction from a central part of the second part towards its periphery, and where the first part comprises means for feeding lubricant from the bearing the second part and means for recirculating lubricant from the second part to the reservoir. 
     
     
       6. The roller mill of  claim 5 , wherein the force-transmitting means is formed as ribs or recesses extending from the central part to its periphery. 
     
     
       7. The roller mill of  claim 6 , wherein the force-transmitting means is either linear or curved.